Place the gammon in a large saucepan and cover with water.
Bring to the boil slowly and allow the heat to penetrate to the centre of the meat.
Simmer for five minutes, then taste the water. If it is too salty, discard it and repeat the process.
If you do this, subtract five minutes from the cooking time.
Add the herbs, onions, carrots and celery to the saucepan and simmer very slowly for three hours.
If you plan to bake a glaze on the ham, subtract an hour from the boiling time.
Once cooked, and if you plan to serve it hot, leave it to cool for about an hour in the cooking liquid.
If you are serving it cold, leave it in its liquid overnight to prevent it from drying out.
Lift it out of the saucepan carefully and peel off the skin, leaving behind a layer of fat.
With a sharp knife, score the fat in a series of diamond shapes, taking care not to cut into the meat.
Press a clove into the centre of each diamond and sprinkle the gammon with cake flour, patting it down loosely.
Put the ham, fat side up, into a large baking dish containing 2 cm of water.
In a saucepan, bring the mustard, honey, sugar and spices to the boil, stirring until the sugar dissolves and the mixture is well combined.
Bake at 180 °C for half an hour, basting with the glaze every 10 minutes during the cooking time.
Serve hot or cold.